基于FPGA无速度传感器直接转矩控制系统

简要介绍当今异步电动机直接转矩控制研究的热点难点，分析了现场可编程逻辑器件(PFGA)速度快、逻辑门数多的优势，实现了自适应无速度传感方案。并以高精度定子磁链圆为目标，提出了磁链圆闭环的方案。仿真结果论证了FPGA在实现调速方案上的显优势。     

提高永磁电机性能的新途径--力矩波动的减小

介绍永磁电机设计技术,通过斜磁钢及合理选择磁极弧度等来减小力矩波动。     

Error categories, detection, and reduction in a musical database

The results of a detailed study of errors in a musical database are presented. It is shown that the form of analytic processing employed may substantially magnify the effect of database errors so that very small error rates can produce very large errors in the analytic results. An equation is devised to assist in estimating the effect of an overall error-rate on arbitrary analytic measures derived from the database. Considering the potential for erroneous or misleading analytic results, it is recommended that scholars using computer-based methods should habitually calculate error rates associated with their analytic procedures, and ought to present an analysis of errors in tandem with their results in order to validate their interpretations.Four methods of error detection are examined: manual proof-reading, double-entry method, programmed syntactic checking, and programmed heuristics. Significant differences were found in the thoroughness of different detection methods in uncovering all errors of a given type. The double-entry method was found to be superior to all other methods of detection; the humanities scholar's traditional allegiance to manual proof-reading was not supported by this study. Programmed methods of error detection were found to be fallible, but nonetheless useful.David Huron is a doctoral student in musicology at the University of Nottingham. He is currently engaged in research in the field of music perception.     

双余度有限转角力矩电动机控制技术

介绍了稀土永磁双余度有限转角力矩电动机（ＬＡＴＭ）位置伺服系统工作原理,就其系统中电气定位,转速与角位移测量,速度位置双闭及双余度控制等进行了研究,文中给出了有关实现电路,并对系统仿真及实验进行了分析。     

摩擦系数在控制预紧力中的应用

介绍螺栓在施加压缩载荷的同时,采用拧紧力矩的方法来测定摩擦系数,再依据这一摩擦系数控制预紧力．此方法在螺栓拧紧过程中测定摩擦特性,而不降低拧紧效率．     

中小型离心风机启动问题

介绍中小型离心 的启动方式及其适应条件,在分析风机负载特性的基础上,简述了风机的启动过程及在风机选型时必须考虑的启动问题。     

带转矩控制技术的ATS 46软起动器

ATS46软起动器是一种特殊的力矩控制系统，它改善了交流感应电动机的起动性能，是其他降压起动方法无可比拟的。重点介绍了ATS46软起动器的方框图、起动特性和优点，并指出采用这种新技术不需要增加用户额外的费用，即可获得优异的传动性能。     

标准麻花钻钻削力的相似预测

本文应用相似理论的原理和现有的切削模型，以很少的切削力数据，简单实用求不同直径麻花钻头钻削力．通过钻削实验确认了钻头切削力相似预测的正确性及适用性．     

自动增力式制动器优化设计研究

本文论讨自动增力式制动器优化设计。在制动器设计中,制动效能因数是个重要因素,故优化设计以制动器的效能因数K_(ef)最大为基础。此方法可以决定制动器结构参数的优化值。结构参数有θ_(01)、θ_1、θ_2、θ_2、e、a等,如简图所示。实例中制动器的效能因数K_(ef)增加(3.2—3.5)％,制动器力矩也增大同样百分比。     

单调扭矩下角钢桁架型钢混凝土构件复合受扭性能研究

针对我国目前型钢混凝土在实际工程中的广泛应用,而国内外对型钢混凝土复合受扭构件研究极少,通过制作3根承受单向压、弯、剪、单调扭矩复合作用下的角钢桁架型钢混凝土构件,以轴压比和扭弯比为研究参数,揭示了角钢桁架型钢混凝土柱复合受扭作用下的破坏特征和裂缝发展规律;对复合受力构件在扭矩作用下的非线性性能（包括扭矩-扭率关系、开裂扭矩、延性和承载力）进行了深入研究.